Bah, I don't buy that. What if your employer tells you you need to take out the spikes in your face? Do you explain to him that it's your individuality and you cannot take them out? You're fired.
When your school tells you to take them out, if you refuse, you're suspended.
There are consequences.
Do I *agree* with the rule? Not really. Teenagers do that stuff, we all know that. But the way I see it, a rule is a rule. When mommy comes to the rescue in order to save her child, who is trying to express himself and all that, she teaches him that "not all rules are important."
Follow the rules. If you don't like it or don't agree with it, question it - but don't break it because you feel it shouldn't apply to you.
Should it be my child, I would back the school in this case. She needs to respect authority, not find ways around it. More power to her if she wants to try and effect change through proper channels.